Re: interval integer comparison - Mailing list pgsql-general

From Bruno Wolff III
Subject Re: interval integer comparison
Date
Msg-id 20050602015322.GA30920@wolff.to
Whole thread Raw
In response to Re: interval integer comparison  (Havasvölgyi Ottó <h.otto@freemail.hu>)
List pgsql-general
On Thu, Jun 02, 2005 at 01:54:12 +0200,
  Havasvölgyi Ottó <h.otto@freemail.hu> wrote:
> Thank you Tom.
>
> It was a bit confusing because my WHERE clause looked something like this:
>
> ... WHERE date_field - current_date < '21 days'::interval;
>
> And then I got records, whose with date_field's year was 2010. :-o
> Now I am using this formula:
>
> ... WHERE date_field < current_date + '21 days'::interval;

If date_field and current_date are realy of type date (and not say
some timestamp varient), then you should use:
... WHERE date_field < current_date + 21

What you used above may have unexpected results near a daylight savings
time change as the data will be promoted to timestamps to do the
comparison.

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